1. Field of the Invention
The present invention relates to an image pickup apparatus, and more particularly to the processing of a video signal obtained from an image pickup device of progressive scan type.
2. Related Background Art
For processing the video signal picked up by a video camera, there has already been known a camcorder. In the conventional apparatus with the NTSC system, the image is recorded and reproduced in interlaced manner at a rate of 60 fields (30 frames) per second.
In case of reproducing a still image in such apparatus, the two fields constituting the image of a frame has a time difference of {fraction (1/60+L )} seconds, so that the image may be blurred because of the difference between the field images in case of a fast moving object. 
For this reason, in case of reproducing a still image it is conceivable to output a field image, but the resolution in the vertical direction is inevitably lowered in such case.
For resolving such drawback, the Japanese Patent Laid-open Application No. 8-205193 proposes, for avoiding the loss of the resolving power in the vertical direction in the interpolation with the image of the other field in a frame, to detect the image movement between the fields and to effect the interpolation with the image of the other field in the frame in an image portion without movement but to effect the interpolation with the image of the same field in an image portion involving movement.
Such method, however, can only increase the vertical resolving power only in portions without movement within the image, and the vertical resolving power still remains low in the portions involving movement.
Besides, the above-described method is unable to avoid the loss of the resolving power in case of slow reproduction, since it is basically used for a moving object. A similar drawback is also encountered in case so-called electronic zooming is executed at the reproduction.
Recently, for the image pickup device of the camcorder, there is being commercialized a CCD of progressive scanning type capable of providing non-interlaced images of 60 frames per second (hereinafter called progressive CCD). The image obtained with such progressive CCD shows little blur in the moving portion of the image even in case of slow reproduction and is free from loss of the vertical resolving power.
However, because of the limitation in the data rate in the recording and reproduction, the conventional camcorder is unable to record all the images of 60 frames per second obtained with such progressive CCD (such images being hereinafter called progressive images). For this reason, in the ordinary moving image pickup mode, the images are recorded by conversion into interlaced images of 60 fields, and, only in the still image pickup mode, there are recorded progressive images of 30 fields.
Therefore, the aforementioned drawbacks are again encountered in case the images recorded in the moving image pickup mode are reproduced as a still image or are slow reproduced.
On the other hand, in such camcorders, the digital video cassette recorders which record the video signal in the digital form are becoming dominant.
Such digital video cassette recorders, because of the feature of handling the image information in the form of digital signals, match well with computers and are recently often utilized for image fetching in the personal computers. The image monitors of the personal computers are mostly displays of progressive scan type. However, as explained in the foregoing, the camcorders including digital ones record and reproduce the interlaced images, so that the taken moving images have to be converted into non-interlaced images in order to be displayed on the monitor of the personal computer. Such conversion results in the deterioration of the image quality as explained in the foregoing, and satisfactory image cannot be displayed.
Consequently, the currently employed progressive CCD has not been effectively utilized.
An object of the present invention is to resolve the drawbacks mentioned above.
Another object of the present invention is to provide a satisfactory image without blur even in case the image involves movement.
Still another object of the present invention is to enable display of a satisfactory image in a progressive monitor.
The above-mentioned objects can be attained, according to an embodiment of the present invention, by an imaging apparatus comprising:
image pickup means for outputting moving image information, obtained with an image pickup device of progressive scan type, in the form of video signals of two channels;
compression means of two systems for respectively compressing the amount of information of the video signals of two channels outputted from the image pickup means; and
transmission means for transmitting, in the compressed state, the video signals of two channels compressed by the compression means of two systems.
Still other objects of the present invention, and the features thereof, will become fully apparent from the following detailed description of the embodiment, to be taken in conjunction with the attached drawings.